Display device, method for manufacturing the device and laser processing apparatus for manufacturing the display device

ABSTRACT

A display device including a linear portion and a curved portion, including a first substrate including a first surface and a second surface opposite the first surface; a second substrate including a third surface and a fourth surface opposite the third surface; and a display panel disposed between the first surface of the first substrate and the fourth surface of the second substrate. An outer surface adjacent to the first surface of the first substrate protrudes outward from an outer surface adjacent to the second surface of the first substrate, and a first width of a region of the first surface of the first substrate that does not overlap with the second surface in the linear portion is greater than a second width of a region of the first surface of the first substrate that does not overlap with the second surface of the first substrate in the curved portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2018-0061012, filed on May 29, 2018, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Field

Exemplary embodiments of the invention relate generally to a displaydevice, a method for manufacturing the display device, and a laserprocessing apparatus for manufacturing the display device.

Discussion of the Background

A display device used for displaying an image typically includes adisplay panel, such as an organic light emitting display panel or aliquid crystal display panel. With development of technology, there isan increasing demand for a display panel with a large display area and adisplay panel having a curved surface. However, the curved display panelmay be more susceptible to impact damage as compared with a rectangularlinear display panel.

Particularly, the curved display panel includes a curved portion and alinear portion according to a shape thereof, in which the linear portiongenerally absorbs the impact in a surface contact form at the time ofexternal impact to disperse the impact, but the curved portion absorbsthe impact in a dot contact form, and thus, may be vulnerable to theimpact. Therefore, studies on a method for processing the curved portionof a curved display panel for improving the problems have beenconducted.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

Exemplary embodiments of the present invention provide a display devicewhich is resistant to external impact by improving an outer side shapeof a curved portion.

Exemplary embodiments of the present invention also provide a method formanufacturing a display device capable of improving an outer side shapeof a curved portion.

Exemplary embodiments of the present invention also provide a laserprocessing apparatus for manufacturing a display device capable ofimproving an outer side shape of a curved portion.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

An exemplary embodiment of the present invention provides a displaydevice including a linear portion and a curved portion, and includes afirst substrate including a first surface and a second surface oppositethe first surface; a second substrate including a third surface and afourth surface opposite the third surface; and a display panel disposedbetween the first surface of the first substrate and the fourth surfaceof the second substrate. An outer surface adjacent to the first surfaceof the first substrate protrudes outward from an outer surface adjacentto the second surface of the first substrate, and a first width of aregion of the first surface of the first substrate that does not overlapwith the second surface in the linear portion is larger than a secondwidth of a region of the first surface of the first substrate that doesnot overlap with the second surface of the first substrate in the curvedportion.

Another exemplary embodiment of the present invention provides a methodof manufacturing a display device, including: providing an object to beprocessed; forming a linear portion of the object to be processed byperforming a first laser processing for the object to be processed; andforming a curved portion of the object to be processed by performing asecond laser processing different from the first laser processing forthe object to be processed.

Another exemplary embodiment of the present invention provides a laserprocessing apparatus, including: an irradiation unit applying a laseronto an object to be processed; and a controller controlling anoperation of the irradiation unit. The controller controls theirradiation unit to form a linear portion of the object to be processedby applying the laser onto the object to be processed according to afirst condition and form a curved portion of the object to be processedby applying the laser onto the object to be processed according to asecond condition different from the first condition.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIG. 1 is a perspective view of a display device according to anexemplary embodiment.

FIG. 2 is a plan view of the display device of FIG. 1.

FIG. 3 is a rear view of the display device of FIG. 1.

FIG. 4 is a cross-sectional view taken along line IV-IV′ of FIG. 2.

FIG. 5 is a detailed cross-sectional view of the display panel of FIG.4.

FIG. 6A and FIG. 6B are cross-sectional views taken along the lines P-P′and Q-Q′, respectively, of FIG. 3.

FIG. 7 is an enlarged view of a region X and a region Y of the displaydevice of FIG. 3.

FIG. 8A and FIG. 8B are cross-sectional views of a display deviceaccording to another exemplary embodiment.

FIG. 9 is a rear view of a display device according to another exemplaryembodiment.

FIG. 10 is a schematic diagram of a laser processing apparatus accordingto an exemplary embodiment.

FIG. 11 is a flowchart for describing a method for manufacturing adisplay device according to an exemplary embodiment.

FIG. 12 and FIG. 13 are views for describing a method for manufacturinga display device according to an exemplary embodiment.

FIG. 14 is a view for describing a method for manufacturing a displaydevice according to an exemplary embodiment.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments or implementations of theinvention. As used herein “embodiments” are non-limiting examples ofdevices or methods employing one or more of the inventive conceptsdisclosed herein. It is apparent, however, that various exemplaryembodiments may be practiced without these specific details or with oneor more equivalent arrangements. In other instances, well-knownstructures and devices are shown in block diagram form in order to avoidunnecessarily obscuring various exemplary embodiments. Further, variousexemplary embodiments may be different, but do not have to be exclusive.For example, specific shapes, configurations, and characteristics of anexemplary embodiment may be used or implemented in another exemplaryembodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z-axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference tosectional and/or exploded illustrations that are schematic illustrationsof idealized exemplary embodiments and/or intermediate structures. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should notnecessarily be construed as limited to the particular illustrated shapesof regions, but are to include deviations in shapes that result from,for instance, manufacturing. In this manner, regions illustrated in thedrawings may be schematic in nature and the shapes of these regions maynot reflect actual shapes of regions of a device and, as such, are notnecessarily intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

In the drawings, components may be exaggerated or reduced in size forconvenience of explanation.

Throughout the specification, like reference numerals refer to likeelements.

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

In this specification, a display device refers to a device for providinglight, and for example, includes devices such as an organic lightemitting display device, an inorganic light emitting display device, anda plasma display device, which display a screen using a lighting deviceor light.

FIG. 1 is a perspective view of a display device according to anexemplary embodiment. FIG. 2 is a plan view of the display device ofFIG. 1. FIG. 3 is a rear view of the display device of FIG. 1.

Referring to FIGS. 1 to 3, a display device 1 may include a displaypanel 400, a first substrate 200 disposed on a lower surface 400 b ofthe display panel 400, and a second substrate 600 provided on an uppersurface 400 a of the display panel 400.

The display panel 400 may have various shapes. For example, the displaypanel 400 may be formed in a shape including a linear portion SA and acurved portion CA, as shown in FIGS. 1 to 3. Specifically, when thedisplay panel 400 has sides formed of straight lines, at least some ofthe edges having an angular shape may be curved. For example, when thedisplay panel 400 has a rectangular shape, a portion where the adjacentstraight sides meet may be replaced by a curved line having apredetermined curvature. That is, vertex portions having a rectangularshape may be formed of curved sides having a predetermined curvature ofwhich both ends adjacent to each other are connected to two straightsides adjacent to each other. Herein, the straight sides configure thelinear portion SA and curved lines having a predetermined curvature mayconfigure a curved portion CA.

The curvature of the curved portion CA may be set differently dependingon the position. For example, the curvature may be changed depending ona position at which the curved line starts and a length of the curveline.

The display panel 400 may display an image. The display panel 400 may bea self-emissive display panel such as, for example, an organic lightemitting display panel (OLED panel), but is not limited thereto. Invarious exemplary embodiments, as the display panel 400, non-emissivedisplay panels such as a liquid crystal display panel (LCD panel), anelectro-phoretic display panel (EPD panel), and an electro-wettingdisplay panel (EWD panel) may be used. When the non-emissive displaypanel is used as the display panel 400, the display device 1 may furtherinclude a back-light unit for providing light to the display panel 400.Hereinafter, an example in which the OLED panel is used as the displaypanel 400 will be described.

The display panel 400 may include a display area DA and a non-displayarea NDA. The display area DA is an area for displaying an image or avideo, and may include a plurality of pixels. Each pixel may be any oneof a red pixel, a green pixel, a blue pixel, and a white pixel, but isnot limited thereto.

For example, the pixel may be any one of a magenta pixel, a cyan pixel,and a yellow pixel. The pixels may have a display element OLED. Such adisplay element OLED may be an organic light emitting element.

The non-display area NDA may be adjacent to display area DA. Forexample, the non-display area NDA may be disposed to surround thedisplay area DA. A pad portion PA may be disposed at one side ofnon-display area NDA. The pad portion PA may include a plurality of padsPD. The pads PD may be a kind of input/output terminal for electricallyconnecting the display panel 400 to other electronic devices, forexample, a flexible printed circuit board (FPCB).

The first substrate 200 may be disposed below the display panel 400. Thefirst substrate 200 may have a different size from the display panel400. For example, the length of the first substrate 200 may be greaterthan the length of the display panel 400.

The first substrate 200 may include a first area and a second area. Thefirst area is an area overlapping with the display panel 400 and thesecond area may be located at one side of the first area and not overlapwith the display panel 400. The second area may have an area smallerthan that of the first area.

The thickness of the first substrate 200 in the first area and thethickness of the first substrate 200 in the second area may be differentfrom each other. That is, a stepped portion having a predeterminedheight h may exist between the first area and the second area. Theheight h of the stepped portion may be smaller than the thickness of thedisplay panel 400.

Although not shown in detail, the display panel 400 and the firstsubstrate 200 may be attached to each other by an adhesive layer. Suchan adhesive layer may include a silicon adhesive as a transparentadhesive material having a high light transmittance and may include anacrylic adhesive, a pressure sensitive adhesive (PSA), an opticallyclear adhesive (OCA), an optically clear resin (OCR), and the like.

The second substrate 600 may be disposed above the display panel 400.The second substrate 600 may have a different size from the displaypanel 400. For example, the length of the second substrate 600 may besmaller than the length of the display panel 400.

The second substrate 600 may be disposed on the display area DA of thedisplay panel 400. Since the length of the second substrate 600 issmaller than the length of the display panel 400, some of the lines orpads PD formed in the non-display area NDA may be exposed to the outsideof the second substrate 600.

Although not shown in detail, the display panel 400 and the secondsubstrate 600 may be attached to each other by an adhesive layer. Suchan adhesive layer may include an acrylic adhesive as a transparentadhesive material having a high light transmittance or may also includea silicon adhesive, a pressure sensitive adhesive (PSA), an opticallyclear adhesive (OCA), an optically clear resin (OCR), and the like.

In an exemplary embodiment, the display device 1 may include a deformedportion DP formed at a point where the linear portion SA and the curvedportion CA meet. Specifically, the deformed portion DP may be formed onthe outer surface where the linear portion SA and the curved portion CAare in contact with each other.

The deformed portion DP may be formed in such a manner that a processingcondition for processing the linear portion SA and that a processingcondition for processing the curved portion CA are different from eachother when the display device 1 is manufactured according to someexemplary embodiments. Although the deformed portion DP is largelyemphasized for ease of understanding in the drawing, the actual size ofthe deformed portion DP may be very small such that the deformed portionDP cannot be visually confirmed. In some exemplary embodiments, theshape of the deformed portion DP may include a depression formed in thesurface of the outer surface, as shown in the drawings.

FIG. 4 is a cross-sectional view taken along line IV-IV′ of FIG. 2. FIG.5 is a detailed cross-sectional view of the display panel of FIG. 4.

Referring to FIGS. 4 and 5, the first substrate 200 may include thelower surface 200 b and the upper surface 200 a. The display panel 400may be disposed on the upper surface 200 a of the first substrate 200.The second substrate 600 may include a lower surface 600 b and an uppersurface 600 a. The display panel 400 may be disposed on the lowersurface 600 b of the second substrate 600. In other words, the displaypanel 400 may be disposed between the upper surface 200 a of the firstsubstrate 200 and the lower surface 600 b of the second substrate 600.

The widths of the first substrate 200, the display panel 400, and thesecond substrate 600 may be decreased in the order of the secondsubstrate 600, the display panel 400, and the first substrate 200, asshown in the drawings. The reason why the shapes of the first substrate200, the display panel 400, and the second substrate 600 are the same asdescribed above is that laser light is incident on the lower surface 200b of the first substrate 200 to manufacture the display device 1.Accordingly, when the laser light is incident to the upper surface 600 aof the second substrate 600, the widths of the first substrate 200, thedisplay panel 400 and the second substrate 600 may be different fromthose shown in the drawings.

Although the widths of the first substrate 200, the display panel 400,and the second substrate 600 are somewhat exaggerated in the drawings soas to show a large difference for a relative comparison, the widthsthereof may have a minute difference which cannot be visuallydistinguished.

The first substrate 200 may include, for example, a support substrate.Specifically, the first substrate 200 may include, for example, aflexible film. More specifically, the first substrate 200 may include acarrier film 210 and a protection and bending film 220.

The first substrate 200 supports the display panel 400 when the displaypanel 400 is bending to prevent the display panel 400 from beingdamaged. The first substrate 200 may include at least one ofpolyethylene terephthalate (PET), polyethylene naphthalate (PEN),polypropylene (PP), polycarbonate (PC), polystyrene (PS), polysulfone(PS), polyethylene (PE), polyphthalamide (PPA), polyethersulfone (PES),polyarylate (PAR), and modified polyphenylene oxide (MPPO).

The display panel 400 may include a plurality of pixel areas includingdriving transistors 430 and 450 and organic light emitting elements 482,484, and 486. The organic light emitting elements 482, 484, and 486 maybe deposited at a relatively low temperature, have low powerconsumption, and implement high luminance to be applied to a flexibledisplay device such as a foldable display device and a rollerabledisplay device.

The pixel area refers to a basic unit for displaying an image, and thedisplay panel 400 may display an image by a plurality of pixel areas. Insome exemplary embodiments, the pixel area may be defined by a pixeldefining film 470 to be described below.

Although only the driving transistors 430 and 450 are shown in FIG. 5,at least one selection transistor for driving the organic light emittingelements 482, 484, and 486, at least one capacitor, and at least one ofdriving transistors 430 and 450 may be arranged in each pixel area.

A substrate 410 may be made of a flexible material. An example of such aflexible material may be a plastic material. Specifically, the substrate410 may be formed of any one selected from the group consisting ofkapton, polyethersulfone, polycarbonate, polyimide, polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polyacrylate (PAR),fiber reinforced plastic (FRP), and the like.

In an exemplary embodiment, the substrate 410 may have a thickness of 5μm to 200 μm. The thickness of the substrate 410 is maintained at 200 μmor less to maintain a flexible characteristic of the substrate 410, andthe thickness of the substrate 410 is maintained at 5 μm or more tosecure stability capable of stably supporting the organic light emittingelements 482, 484, and 486.

A buffer layer 420 may be disposed on the substrate 410. The bufferlayer 420 may serve to prevent impure elements from being penetrated andplanarize the surface thereof. The buffer layer 420 may be made of anyone of, for example, a silicon nitride (SiN_(x)) film, a silicon oxide(SiO₂) film, a silicon oxynitride (SiO_(x)N_(y)) film, or the like.However, such a buffer layer 420 is not necessarily required, and mayalso be omitted according to a type of substrate 410 and devicemanufacturing process conditions.

A semiconductor layer 430 may be disposed on the buffer layer 420. Thesemiconductor layer 430 may include any one of a polycrystalline siliconfilm (poly Si), an amorphous silicon film (amorphous Si), and an oxidesemiconductor, such as indium-gallium-zinc oxide (IGZO) and indium zinctin oxide (IZTO). For example, when the semiconductor layer 430 includesthe polycrystalline silicon film, the semiconductor layer 430 mayinclude a channel region 434 in which impurities are not doped, and asource region 432 and a drain region 436 which are formed on both sidesof the channel region by doping impurities.

The types of impurities doped into the source region 432 and the drainregion 436 may vary depending on the types of the driving transistors430 and 450. In some embodiments, P-type transistors doped with P-typeimpurities may be used in the source region 430 and the drain region 432as the driving transistors 430 and 450, but the inventive concepts arenot limited thereto.

A gate insulating film 440 may be disposed between the semiconductorlayer 430 and the gate electrode 450. The gate insulating film 440 mayinclude an insulating film. For example, the gate insulating film 440may include at least one of silicon nitride (SiN_(x)) and silicon oxide(SiO₂). In an exemplary embodiment, the gate insulating film 440 mayalso be formed of a multilayer structure including a double-layer filminstead of a single film.

The gate electrode 450 may be disposed on the gate insulating film 440.The gate electrode may extend in one direction to be connected to a gateline. The gate electrode 450 may be disposed so as to overlap with thechannel region 434. The gate electrode 450 may include at least one of,for example, molybdenum (Mo), chromium (Cr), tungsten (W), titanium(Ti), and copper (Cu). In addition, although not shown in detail, afirst electrode of the capacitor may be disposed on the gate insulatingfilm 440.

An interlayer insulating film 445 may be disposed on the gate electrode450. The interlayer insulating film 445 may be disposed so as tocompletely cover the gate electrode 450. The interlayer insulating film445 may include silicon nitride (SiN_(x)), silicon oxide (SiO_(x)),tetraethoxysilane (TEOS) or the like, similarly to the gate insulatingfilm 440, but the inventive concepts are not limited thereto.

A data line including the source electrode 452 and the drain electrode454 may be disposed on the interlayer insulating film 445. Although notshown in detail, a second electrode of the capacitor may also bedisposed on the interlayer insulating film 445. In an exemplaryembodiment, the source electrode 452 and the drain electrode 454 mayalso be formed in the form of a multilayer film having a double film ormore, and in this case, the interlayer insulating film 445 may bedisposed between the multilayers.

The source electrode 452 and the drain electrode 454 may be connected tothe source region 432 and the drain region 436 through via holes formedin the gate insulating film 445 and the interlayer insulating film 545,respectively. At this time, as shown in the drawing, vias are formed inthe via holes so that the source electrode 452 and the drain electrode454 may be connected to the source region 432 and the drain region 436,respectively.

The drain electrode 454 may be connected to a pixel electrode 482 of theorganic light emitting elements 482, 484, and 486 through a via formedin a planarization layer 460.

The driving transistors 430 and 450 may provide a driving signal to thepixel electrode 482 to emit light of the light emitting layer 484 of theorganic light emitting elements 482, 484, and 486 in the selected pixelarea.

Specifically, a voltage corresponding to a difference between a datavoltage supplied from the data line and a common voltage supplied from acommon power supply line is stored in the capacitor, and a drivingcurrent corresponding to the voltage stored in the capacitor runs to theorganic light emitting elements 482, 484, and 486 through the drivingtransistors 430 and 450 to emit light in the organic light emittingelements 482, 484, and 486.

The planarization film 460 may be disposed on the interlayer insulatingfilm 445 so as to cover the source electrode 452 and the drain electrode454. The planarization film 460 may serve to remove and planarize a stepin order to increase emission efficiency of the organic light emittingelements 482, 484, and 486 to be disposed thereon. The planarizationfilm 460 may include at least one material of, for example, apolyacrylate-based resin, an epoxy resin, a phenolic resin, apolyamide-based resin, a polyimide-based resin, an unsaturatedpolyester-based resin, a polyphenylenether-based resin, apolyphenylenesulfide-based resin, and benzocyclobutene (BCB).

The pixel electrode 482 of the organic light emitting elements 482, 484,and 486 may be disposed on the planarization film 460. The pixelelectrode 482 may be electrically connected to the drain electrode 454through a via formed in the planarization film 460.

The pixel defining film 470 may be disposed to expose a part of thepixel electrode 482. The pixel defining film 470 may define a pixel areaof the display area DA (see FIG. 1) and the pixel electrode 482 may bedisposed to correspond to the pixel area by the pixel defining film 470.

The pixel defining film 470 may include a resin such as apolyacrylate-based resin or polyimides.

The light emitting layer 484 may be disposed on the pixel electrode 482in the pixel area and a common electrode 486 may be disposed on thepixel defining film 470 and the light emitting layer 484. The lightemitting layer 484 may be formed of a low molecular organic material ora high molecular organic material. Although not shown in detail, thelight emitting layer 484 may include a hole injection layer (HIL) and ahole transporting layer (HTL) which are disposed adjacent to the pixelelectrode 482. Further, the light emitting layer 484 may include anelectron transporting layer (ETL) and an electron injection layer (EIL)disposed adjacent to the common electrode 486.

In an exemplary embodiment, the pixel electrode 482 and the commonelectrode 486 may be formed as a transmissive electrode or atransflective electrode. Accordingly, the light generated in the lightemitting layer 484 may be provided to the outside through the uppersurface 400 a and the lower surface 400 b of the display panel 400.

In an exemplary embodiment, the pixel electrode 482 may be formed as areflective electrode and the common electrode 486 may be formed as atransmissive electrode or a transflective electrode. Accordingly, thelight generated in the light emitting layer 484 may be provided in adirection of the upper surface 400 a of the display panel 400.

For example, a transparent conductive oxide (TCO) may be used forforming a transmissive electrode. Examples of the transparent conductiveoxide (TCO) may include indium tin oxide (ITO), fluorine doped tin oxide(FTO), indium zinc oxide (IZO), zinc oxide (ZnO), aluminum doped ZnO(AZO), gallium doped ZnO (GZO), boron doped ZnO (BZO), indium oxide(In2O3), or the like. In addition, metal nanowires and carbonnanomaterials may be used. For example, silver nanowires (Ag-NW), carbonnanotubes, carbon nanowires, fullerene, graphene, and the like may beused.

For forming the transflective electrode, a metal such as magnesium (Mg),silver (Ag), gold (Au), calcium (Ca), lithium (Li), chromium (Cr),aluminum (Al), and copper (Cu) or alloys thereof may be used. At thistime, the pixel electrode 482 and the common electrode 486 may be formedas the transflective electrodes by controlling the thickness of theelectrode. As the thickness of the transflective electrode becomessmaller, the transmittance of light increases, but the resistanceincreases. In addition, the greater the thickness, the lower thetransmittance of light.

Further, the transflective electrode may be formed as a multilayerstructure including a metal layer made of a metal or a metal alloy and atransparent conductive oxide (TCO) layer laminated on the metal layer.

A thin film encapsulation layer 490 may be disposed on the commonelectrode 486. The thin film encapsulation layer 490 may includeinorganic films 492 and 496 and an organic film 494. In an exemplaryembodiment, the thin film encapsulation layer 490 may be disposed in aform in which the inorganic films 492 and 496 and the organic film 494are alternately laminated. Further, the inorganic films 492 and 496 andthe organic film 494 may also laminated with inorganic films and organicfilms more than those shown in the drawing.

A lower inorganic film 492 may be disposed nearest to the organic lightemitting elements 482, 484, and 486.

The lower inorganic film 492 may include at least one inorganic materialof Al₂O₃, TiO₂, ZrO, SiO₂, AlON, AlN, SiON, Si₃N₄, ZnO, and Ta₂O₅. Thelower inorganic film 492 may be formed by a method such as a chemicalvapor deposition (CVD) method or an atomic layer deposition (ALD)method. Accordingly, the lower inorganic film 492 may be conformallydisposed according to the shape of the common electrode 486 as shown inthe drawing. The upper inorganic film 496 may include the same materialas the lower inorganic film 492.

The organic layer 494 may include a polymer-based material. Here, thepolymer-based material may include an acrylic resin, an epoxy resin,polyimide, polyethylene, and the like. The organic film 494 may beformed through a thermal deposition process. At this time, the thermaldeposition process for forming the organic film 494 may be performedwithin a temperature range without damaging the organic light emittingelements 482, 484, and 486.

The inorganic films 492 and 486, in which the thin film is formed tohave a high density, may serve to mainly suppress the permeation ofmoisture or oxygen.

The thin film encapsulation layer 490 may be formed to, for example, athickness of 10 μm or less. Accordingly, the overall thickness of thedisplay panel 400 may be made very small. As such, the thin filmencapsulation layer 490 is applied to maximize a flexible characteristicof the display panel 400.

The second substrate 600 may include, for example, an optical substrate.In particular, the second substrate 600 may include, for example, apolarization plate.

The second substrate 600 may include a linear polarization layer 620 anda phase difference layer 610. The phase difference layer 610 may bedisposed between the thin film encapsulation layer 490 and the linearpolarization layer 620.

The linear polarization layer 620 may transform natural light or anypolarization light into linear polarization light in a specificdirection, and may reduce reflection of external light. A polarizationaxis of the phase difference layer 610 may be inclined at an angle of45° with respect to a polarization axis of the phase difference layer610.

The phase difference layer 610 may shift phase of the light incident onthe phase difference layer 610 by ¼λ. That is, since the phasedifference layer 610 shifts the phase of the incident light by ¼λ, it ispossible to convert linear polarization light into circular polarizationlight or circular polarization light into linear polarization light.

The second substrate 600 may prevent reflection of external light asfollows. First, external light can pass through the linear polarizationlayer 620. Here, the light passing through the linear polarization layer620 may be linear polarization light having only a componentperpendicular to the polarization axis of the linear polarization layer620.

The light passing through the linear polarization layer 620 may passthrough the phase difference layer 610. The light passing through thephase difference layer 610 may be circular polarization light in whichthe phase is shift by ¼λ by the phase difference layer 610.

The light passing through the phase difference layer 610 may bereflected on the display panel 400. The light reflected on the displaypanel 400 (hereinafter referred to as “reflected light”) may maintain acircularly polarized state. This reflected light may pass through thephase difference layer 610 again. In the reflected light passing throughthe phase difference layer 610, the phase may be shift by ¼λ by thephase difference layer 610. The reflected light reflected on the displaypanel 400 may be linear polarization light. Here, the reflected lightpassing through the phase difference layer 610 may be parallel to thepolarization axis of the linear polarization layer 620. Accordingly, thereflected light passing through the phase difference layer 610 may notpass through the linear polarization layer 620, but may be absorbed bythe linear polarization layer 620. Accordingly, the second substrate 600may prevent external light incident to the display device 1 from beingreflected. As such, when the reflection of external light is preventedby the second substrate 600, the contrast of the display device 1 may beimproved.

FIGS. 6A and 6B are cross-sectional views taken along the lines P-P′ andQ-Q′, respectively, of FIG. 3 and FIG. 7 is an enlarged view of a regionX and a region Y of the display device of FIG. 3.

Referring to FIGS. 6A and 6B, an outer surface OS1 (see a cut section ofP-P′) of the linear portion SA of the display device 1 may be differentfrom an outer surface OS1 (see a cut section of Q-Q′) of the curvedportion CA. Specifically, the slope of the outer surface OS1 of thecurved portion CA may be greater than the slope of the outer surface OS1of the linear portion SA. According to the shape of the outer surfaceOS1, an edge portion of the outer surface OS1 of the curved portion CAof the display device 1 (for example, a portion where the outer surfaceis adjacent to the upper surface of the second substrate 600) may be notsharp but blunt instead. This shape of the outer surface OS1 of thecurved portion CA allows the curved portion CA to withstand the externalimpact better. Thus, the reliability of the display device 1 may beimproved.

Specifically, in the both the linear portion SA and the curved portionCA, the outer surface OS1 of the display panel 400 may protrude outwardfrom the outer surface of the first substrate 200 and the outer surfaceOS1 of the second substrate 600 may protrude outward from the outersurface of the display panel 400. At this time, the degree of protrusionof the outer surface of the linear portion SA may be greater than theprotrusion degree of the outer surface of the curved portion CA.

More specifically, a width W1 of a region of the upper surface 200 a(see FIG. 4) of the first substrate 200 which does not overlap with thelower surface 200 b (see FIG. 4) in the linear portion SA may be largerthan a width W2 of a region of the upper surface 200 a (see FIG. 4) ofthe first substrate 200 that does not overlap with the lower surface 200b (see FIG. 4) in the curved portion CA.

Such a shape shown in the drawing may be caused because the laser lightis incident from the first substrate 200 to the second substrate 600 tocut the display device 1. If the laser light is incident from the secondsubstrate 600 to the first substrate 200 to cut the display device 1,the shape of the outer surface OS1 may be formed differently.

Furthermore, an angle A1 between the outer surface OS1 and the lowersurface of the first substrate 200 in the linear portion SA may belarger than an angle A2 between the outer surface OS1 and the lowersurface of the first substrate 200 in the curved portion CA. Further, anangle A3 between the upper surface 600 a (see FIG. 4) and the outersurface OS1 of the second substrate 600 in the linear portion SA may besmaller than an angle A4 between the upper surface 600 a (see FIG. 4)and the outer surface OS1 of the second substrate 600 in the curvedportion CA.

In an exemplary embodiment, a length LE1 of the outer surface OS1extending from the lower surface 200 b (see FIG. 4) of the firstsubstrate 200 to the upper surface 600 a (see FIG. 4) of the secondsubstrate 600 in the linear portion SA may be larger than a length LE2of the outer surface OS1 extending from the lower surface 200 b (seeFIG. 4) of the first substrate 200 to the upper surface 600 a (see FIG.4) of the second substrate 600 in the curved portion CA.

Referring to FIG. 7, the display device 1 may include different types ofheat affected zones HAs in the linear portion SA and the curved portionCA. Particularly, a width W3 of the heat affected zone HA formed to beadjacent to the outer surface of the linear portion SA may be greaterthan a width W4 of the heat affected zone HA formed to be adjacent tothe outer surface of the curved portion CA. The shape of the heataffected zone HA may be caused because a laser processing recipe of thelinear portion SA is different from a laser processing recipe of thecurved portion CA. A more detailed description thereof will be givenwhile describing a method of manufacturing a display device according toexemplary embodiments.

FIGS. 8A and 8B are cross-sectional views of a display device accordingto another exemplary embodiment. Hereinafter, the duplicated descriptionof the exemplary embodiments described above will be omitted anddifferences will be mainly described.

Referring to FIG. 8A and FIG. 8B, an outer side OS2 (see a cut sectionof P-P′) of a linear portion SA of a display device 2 may be differentfrom an outer side OS2 (see a cut section of Q-Q′) of a curved portionCA. and the shape of the outer side OS2 may be different from theexemplary embodiment described with reference to FIGS. 6A and 6Bdescribed above.

A width W1 of a region of the upper surface of the first substrate 200,which does not overlap with the lower surface in the linear portion SAmay be greater than a width W2 of a region of the upper surface of thefirst substrate 200, which does not overlap with the lower surface inthe curved portion CA. According to the shape of the outer surface OS2,an edge portion of the outer surface OS2 of the curved portion CA of thedisplay device 2 may be not sharp but blunt. Such a shape of the outersurface OS2 of the curved portion CA allows the curved portion CA towithstand the external impact better. Thus, the reliability of thedisplay device 2 may be improved.

FIG. 9 is a rear view of a display device according to still otherexemplary embodiments. Hereinafter, the duplicated description of theexemplary embodiments described above will be omitted and differenceswill be mainly described.

Referring to FIG. 9, a display device 3 may include a deformed portionPP formed at a point where the linear portion SA and the curved portionCA meet. Specifically, the deformed portion PP may be formed on theouter surface where the linear portion SA and the curved portion CA arein contact with each other.

Such a deformed portion PP may be formed in such a manner that when thedisplay device 3 is manufactured, processing conditions for processingthe linear portion SA and processing conditions for processing thecurved portion CA are different from each other. Although the deformedportion PP is largely shown to be emphasized for ease of understandingin the drawing, the actual size of the deformed portion PP may be smallenough not to be visually checked. In some exemplary embodiments, theshape of the deformed portion PP may include protrusions that protrudefrom the surface of the outer surface as shown in the drawing.

FIG. 10 is a schematic diagram of a laser processing apparatus accordingto another exemplary embodiment of the present invention.

Referring to FIG. 10, a laser processing apparatus may include anirradiation unit 1000 and a controller 1010.

The irradiation unit 1000 may apply laser light L onto an object 2000 tobe processed. Specifically, the irradiation unit 1000 may cut the object2000 to be processed into a desired shape by applying the laser light Lonto the object 2000 to be processed.

In some exemplary embodiments, the object 2000 to be processed mayinclude the first substrate 200, the display panel 400, and the secondsubstrate 600, as shown in FIG. 1. That is, the laser processingapparatus shown in FIG. 10 may be an apparatus of cutting the object2000 to be processed including the first substrate 200, the displaypanel 400, and the second substrate 600 to have the linear portion SA(see FIG. 2) and the curved portion CA (see FIG. 2).

The controller 1010 may control an operation of the irradiation unit1000. Specifically, the controller 1010 may control a power level of thelaser light L applied by the irradiation unit 1000, a moving speed ofthe laser light L applied by the irradiation unit 1000, and the numberof times the laser light L is applied. Here, the moving speed of thelaser light L may be a speed at which the irradiation unit 1000 moveswhile applying the laser light L onto the object 2000 to be processed,but the inventive concepts are not limited thereto. In another exemplaryembodiment, the moving speed of the laser light L may be a speed atwhich the object 2000 to be processed is moved by applying the laserlight L onto the object 2000 to be processed in a state where theirradiation unit 1000 is stopped.

Hereinafter, a method for manufacturing a display device will bedescribed with reference to FIGS. 11 to 13. The method for manufacturingthe display device to be described below may be performed using, forexample, the laser processing apparatus described in FIG. 10, but theinventive concepts are not limited thereto.

FIG. 11 is a flowchart for describing a method for manufacturing adisplay device according to an exemplary embodiment of the presentinvention. FIGS. 12 and 13 are views for describing a method formanufacturing a display device according to this exemplary embodiment ofthe present invention.

First, referring to FIG. 11, an object to be processed is provided.Then, the linear portion of the object to be processed is processedunder the first condition (S100).

Specifically, referring to FIG. 12, it is possible to perform a firstlaser processing of forming the linear portion in the object 2000 to beprocessed by applying the first laser light L1 onto the object to beprocessed 2000. Here, the first laser processing may include applying afirst laser light L1 having high energy onto the object 2000 to beprocessed repeatedly n times (where n is a natural number) by moving thefirst laser light L1 at a relatively low speed to the object 2000 to beprocessed. Here, the applying of the first laser light L1 repeatedly ntimes may include applying the first laser light L1 repeatedly n timesalong a contour of the shape of the linear portion shown in FIG. 12.Exemplary values for the first condition are described in Table 1 below.

TABLE 1 First condition - linear Second condition - curved Items portionportion Laser power 18 to 26 W 8 to 12 W level Moving 220 to 250 mm/s5,000 to 7,000 mm/s speed Scan times 2 to 6 times 120 to 160 times

Referring back to FIG. 11, the curved portion of the object to beprocessed is processed under the second condition (S110).

Specifically, referring to FIG. 13, it is possible to perform a secondlaser processing of forming the curved portion in the object 2000 to beprocessed by applying the first laser light L2 onto the object to beprocessed 2000. Here, the second laser processing may include, forexample, applying a second laser light L2 having low energy onto theobject 2000 to be processed repetitively m times (where m is a naturalnumber) by moving the second laser light L2 at a relatively high speedto the object 2000 to be processed in which the processing of the linearportion SA is completed. Similarly, the irradiation of the second laserlight L2 repeatedly m times may include applying the second laser lightL2 repeatedly m times along a contour of the shape of the curved portionshown in FIG. 12. Exemplary values for the second condition are alsodescribed in Table 1 above.

In an exemplary embodiment, the deformed portions DPs (see FIGS. 2 and3) may be formed in a region R where the first laser processing and thesecond laser processing proceed simultaneously. These deformed portionsDPs (see FIGS. 2 and 3) may include depressions formed in the surface.

FIG. 14 is a view for describing a method for manufacturing a displaydevice according to an exemplary embodiment of the present invention.Hereinafter, the duplicated description of the exemplary embodimentsdescribed above will be omitted and differences will be mainlydescribed.

Referring to FIG. 14, the method for manufacturing the display deviceaccording to this exemplary embodiment is different from theabove-described exemplary embodiment in the second laser processingmethod for processing the curved portion. Specifically, in the exemplaryembodiment described with reference to FIG. 13 above, the second laserlight L2 is applied with a contour that forms an acute angle with thelinear portion SA that has been processed, but in the present exemplaryembodiment, as shown in FIG. 14 the second laser light L2 may be appliedwith a contour that forms a substantially right angle to the linearportion SA that has been processed. Accordingly, the shape of thedeformed portion formed in a region S in which the first laserprocessing and the second laser processing proceed simultaneously may bedifferent from the embodiment described above. Specifically, thedeformed portion PP (see FIG. 9) described above may be formed in theregion S in which the first laser processing and the second laserprocessing proceed simultaneously. Such a deformed portion PP (see FIG.9) may include a protrusion protruding from the surface.

According to the display device and the method for manufacturing thedisplay device according to the exemplary embodiments, it is possible toallow the curved portion to sufficiently withstand external impacts byimproving a shape of an edge portion of an outer side of the curvedportion of the display device. Therefore, it is possible to improvereliability of the display device.

Although certain exemplary embodiments have been described herein, otherembodiments and modifications will be apparent from this description.Accordingly, the inventive concepts are not limited to such embodiments,but rather to the broader scope of the appended claims and variousobvious modifications and equivalent arrangements as would be apparentto a person of ordinary skill in the art.

What is claimed is:
 1. A display device including a linear portion and acurved portion, comprising: a first substrate comprising a first surfaceand a second surface opposite the first surface; a second substratecomprising a third surface and a fourth surface opposite the thirdsurface; and a display panel disposed between the first surface of thefirst substrate and the fourth surface of the second substrate, wherein:an outer surface adjacent to the first surface of the first substrateprotrudes outward from an outer surface adjacent to the second surfaceof the first substrate; and a first width of a region of the firstsurface of the first substrate that does not overlap with the secondsurface in the linear portion is greater than a second width of a regionof the first surface of the first substrate that does not overlap withthe second surface of the first substrate in the curved portion.
 2. Thedisplay device of claim 1, wherein an angle between the outer surface ofthe first substrate and the second surface of the first substrate in thelinear portion is greater than an angle between the outer surface of thefirst substrate and the second surface of the first substrate in thecurved portion.
 3. The display device of claim 1, wherein an anglebetween the outer surface of the second substrate and the third surfaceof the second substrate in the linear portion is less than an anglebetween the outer surface of the second substrate and the third surfaceof the second substrate in the curved portion.
 4. The display device ofclaim 1, wherein a first length of the outer surface extending from thesecond surface of the first substrate to the third surface of the secondsubstrate in the linear portion is greater than a second length of theouter surface extending from the second surface of the first substrateto the third surface of the second substrate in the curved portion. 5.The display device of claim 1, wherein the first substrate comprises aheat affected zone formed to be adjacent to the outer surface and afirst width of the heat affected zone formed in the linear portion isdifferent from a second width of the heat affected zone formed in thecurved portion.
 6. The display device of claim 5, wherein the firstwidth is greater than the second width.
 7. The display device of claim1, wherein the first substrate comprises a deformed portion formed on anouter surface where the linear portion and the curved portion are incontact with each other.
 8. The display device of claim 7, wherein thedeformed portion comprises a depression formed in the surface.
 9. Thedisplay device of claim 7, wherein the deformed portion comprises aprotrusion protruding from the surface.
 10. The display device of claim1, wherein the first substrate comprises a support substrate, and thesecond substrate comprises an optical substrate.
 11. The display deviceof claim 10, wherein the support substrate comprises a flexible film,and the optical substrate comprises a polarization plate.